The instant invention deals with an improved fume hood having a trimodal piston driven sash operator. More specifically, this invention deals with fume hoods which are state of the art fume hoods, which have been further improved by the addition of a travel interference system for the moveable sash of such a hood.
Fume hoods are a common item of most every chemical laboratory and have been employed in one form or another for many years. As new materials and techniques are evolved, the fume hood undergoes modifications to attempt to ensure working personnel freedom from spills and burns, noxious gases and chemicals.
Most recently, a patent was issued to the inventors named herein, i.e. U.S. Pat. No. 4,774,878, which issued on Oct. 4, 1988, in which there is described a trimodal piston driven sash operator for use in fume hoods.